If you are one of the keen folks, you might have already noticed how phones with fast charging have smaller batteries. I personally had not, but an interesting study by GSMArena across a few phones from different brands seems to be backing this claim.
To narrow down as possible and to remove as much outside interference as possible, things like different release dates and other variables, the team at GSMArena chose devices from the same maker, that launched around the same time and also have the same dimensions, with the only difference being the charging speeds.
This was mostly a straightforward process, as there are a few phones where the only difference between the vanilla version and its Pro model is the increased charging speeds.
Battery capacity cost for fast charging feature
Based on an average of 12 pairs of devices, (a pair consisting of the slow charging model with its fast-charging variant) the capacity lost is 10 percent. This means, if the slow charging variant has a 5,000 mAh battery, its fast-charging counterpart will most likely have a 4,500 mAh one.
Here are a few examples partnered with their fast charging variants;
- Xiaomi Redmi Note 11 Pro(China), 5,160mAh, 67W – Xiaomi 11i HyperCharge 5G, 4500mAh, 120W
- Vivo Y72 5G, 5,000mAh, 18W – iQOO Z3, 4,400mAh, 55W
- Xiaomi Mi10 5G, 4780mAh, 30W – Xiaomi Mi 10 Pro 5G 4,500mAh, 50W
- Xiaomi Redmi K50 5,500mAh, 67W – Xiaomi Redmi K50 Pro, 5,000mAh, 120W
- iQOO Z5 5,000mAh, 44W – iQOO Neo5 SE, 4,500, 55W
In the 5 examples above, the phone variants with faster charging all have noticeably smaller batteries, which averages to about 90% of their slower charging counterparts
In their report, GSMArena notes that phones moving from 18W charging to 30W charging do not have a noticeable hit to their battery capacities, as is the case from 30W to 67W or other higher figures like 120W.
For instance, the Redmi Note 9 Pro(Indian version) and the global Redmi Note 9 Pro have the same battery capacities at 5,020mAh with the only difference being their charging speeds, the Indian version clocking at 18W while the global version supports 30W charging.
What does this tell us?
Going from 18W slow charging to around 25W-35W does not cost the battery’s capacity while moving from 30W to 65W takes a hit of around 10% in capacity and further moving from 65W to 120W is another 15% hit to the battery.
30W charging will juice a dead 5,000mAh battery to 100% in slightly more than one hour, while 65W will do the same in about 45 minutes and the extreme 120W will top up the battery in 20 minutes flat.
It comes down to taste and preference, whether the faster charging times are worth the loss in battery capacity. You are able to charge your device much faster, but you will also need to charge it more regularly. It is basically a double-edged sword.
However, things do not have to be so clear-cut and defined, you can still use your old slow charging adapter to leave your phone overnight when you go to sleep. You wake up when it is at 100%, and you do not suffer the quick battery degradation issues that fast charging introduces.